Year % (national estimate) 1966 3.52428242703161 1975 4.091022133797563 1977 5.276346930251984 1983 7.2274881516587675 1984 8.667056416252557 1985 12.287525208873522 1987 10.18324607329843 1996 15.259488768396592 1997 15.574809805579036 2000 14.164004259850904 2009 20.317506554034374 2010 20.563462097008422 2012 23.303834808259587 2013 23.884892086330936 2014 23.520352699601403 2015 24.38951400526694 2016 25.478665002180882